There is an increasing awareness that logging, road building and other similar operations in remote locations can cause significant environmental damage to fish habitat. Many species of fish spawn in small creeks which are particularly vulnerable to hydrocarbon spills or run-off containing sediment. Destruction of fish habitat can have a profound adverse affect on the whole forest ecosystem.
Some jurisdictions have recently imposed stringent regulations to limit the environmental impact of logging operations. The need has therefore arisen for improved pollution control devices which are particularly suited for temporary installation to protect creeks in remote locations.
One conventional approach for trapping sediment is to stack hay bales in a creek bed downstream from logging operations. The hay bales effectively function as an organic filter permitting the flow of water while acting as a barrier blocking the passage of sediment to downstream locations of the creek. A major shortcoming of this approach is that sediment which accumulates on the upstream side of the hay bales remains in the waterway and is often dispersed downstream when the hay bales are removed and the creek returns to its normal flow pattern.
"Silt fences", which consist of sheets of woven polypropylene installed to extend across small waterways, suffer from the same limitation. The sheets allow the flow of water therethrough but trap sediment fines. However, not all of the fines settle on the creekbed and they may be dispersed downstream when the sheets are removed from the creek after the upstream logging operations or the like have been completed.
Conventional hay bale and silt fence barriers are also not capable of effectively containing hydrocarbon spills. While a great many hydrocarbon containing devices and methods are known in the prior art, the applicant is not aware of any prior art structures which are particularly adapted for spanning small waterways in conjunction with a sediment trap.